Combined sewing and trimming mechanism



Dec. 16, 1952 D, TAYLOR 2,621,618

COMBINED SEWIMG AND TRIMMING MECHANISM Filed Sept. 4, 1948 5Sheets-Sheet l a/= as. 5 A5 39 Zmventor 16, a T. D. TAYLOR 2,621,618

COMBINED SEWING AND TRIMMING MECHANISM" Filed Sept. 4, 1948 5Sheets-Sheet 3 8 H 77 E/7/ll/lll Ill/ 1I I a, Z 2

3nventor Won/)4; 0. 72mm? (Ittomeg Patented Dec. 16, 1952 COMBINEDSEWING AND TRIMMING MECHANISM Thomas D. Taylor, University City, Mo.,assignor to Columbia Sewing Machine Corporation, a

corporation of New York Application September 4, 1948, Serial No. 47,930

13 Claims.

The invention herein disclosed relates to a combined sewing and edgetrimming mechanism and comprehends an attachment'for a sewing machine bywhich the ordinary sewing machine is converted to a combined sewing andedge trimming mechanism.

The principal object of the invention is to provide an arrangementwhereby the ordinary sewing machine is readily and easily converted intoa combined sewing and trimming mechanism. Another object of theinvention is to provide a trimming attachment for a sewing machine thatmay be afiixed to the sewing machine without the necessity of anymachining operations on the sewing machine. A further object of theinvention is to provide a pinking arrangement that utilizes cooperatingrelativelymovable V-shaped knives which pinking arrangement isreadilythe work table in section, embodying my invention;

Fig. 2 which is a partial side elevation of the same;

Fig. 3 which is a plan of a pinking attachment, embodying the invention,taken on the irregular line 33 of Fig. 2;

Fig. 4 which is a sectional, side elevation of the same taken on theline l-:lof Fig. 3;

Fig. 5 which is a partial, sectional, side elevation of the same, takenon the line 5-5 of Fig. 3;

Fig. 6 which is also a partial, sectional, side elevation of the same,taken on the 1ine6--5 of Fig. 3;

Fig. 7 which is a sectional, end elevation of the same, taken on theline 1-1 of Fig. 2;

Fig. 8 which is a sectional, end eelvation of the same taken on the line8-.-8 of Fig. 2;

Fig. 9 which is a sectional elevation taken on the line 8-9 of Fig. 4;

Fig. 10 which is an enlarged, partial, front, end elevation of thepresser foot showing the position of the cloth in the sc-called plainstitching and pinking operation;

Fig. 11 which is a view similar to Fig. 10 showing the cloth in theso-calledtop-stitching and pinking operation; and

Fig. 12 which is a similar view of a modified foot and guide suitablefor the plain stitching and pinking operation.

In general, the arrangement illustrated in the drawing includes themechanism of the compart of the sewing machine includes the needleheadI, the work table 2 and the feed dog3. Slidably mounted in theneedle-head i, thereiis the usual presser-foot bar 4 that is resilientlyurged toward the work table 2, and the needle bar 5 that is reciprocatedvertically in the usual manner. cooperates with a rotary hook I for theformation of stitches. The feed dogs 3 are actuated in the usual mannerto advance the cloth being sewn, from right to left as seen in Fig. 1.All of the operating mechanism for such a sewing machine is old and wellknown in the art, and it has not, therefore, in the interest ofproviding aclear illustration of the invention, been disclosed in thedrawing.

The particular trimming arrangement disclosed is for serrating orpinking the edge of material being sewn; it is of the kind that utilizescooperating, relatively movable, male and female V-shaped pinkingknives. The female knife 8 consists of a plate having a slot 9 cutthrough from one end edge thereof and terminating in converging,U-shaped cutting edges l0 and IL. The plate 8 is secured, by machinescrews l2 and [3, to a presserfoot, designated generally by the numeral14.

The presser foot [4 includes a shank portion l5 and a foot l6 thatextends forwardly of the shank. The shank I5 is relatively wide and hasalongitudinal groove I! that receives the end portion I8 of thepresser-foot bar to which it is secured by a machine screw Illa. Theside of the end portion ll; of the presser-foot bar that engagesthe baseof the groove I1 is flattened to prevent relativeturning of thepresserfoot with respect to the presser-footbar. An opening lS' isprovided, through the shank, that corresponds v with, and has edgesaligned with the edgesof the lower portion of the slot 9 through thefemale knife 8.

The foot I6 has a needle opening'zll therethrough through which theneedle reciprocates to cooperate with the hook I. In addition, thefoothas a longitudinal slot 21 therethrough (Fig.- 2),. This slot has a sidewall 22 that turns thejedg e of the cloth being sewn, andto be pinked,vertically and guides the edge intocutting relation with respect to thefemale knife, to the right of the femaleknife, as seen in' Figs. 2 and4. To this end the wall 22 diverges from the engaging face of the footand curves to the vertical. The

edge of the cloth entering the slot is thus, as it passes through theslot turned vertically, pre- The needle bar carries a needle 6 thatsented to and moved past the cutting edges of the female knife.

A V-shaped, male knife 23 is reciprocated in a plane parallel to thework table, at right angles to the plane containing the axis of thepresserfoot and needle bars 4 and 5, and cooperates with the femaleknife. The male knife and the actuating mechanism therefor are carriedby a bracket 24 that is clamped to the presser-foot bar 4 above thepresser foot. An end face 25 of the bracket 24 has a semi-cylindricalslot 23 therein and a clamping bracket 2'! has a like semi-cylindricalslot 23 therein. The slots 26 and 28 are such that when the presser-footbar is received therein and the brackets secured together by machinescrews 29 and 30, one on each side of the presser-foot bar, the bracket24 is firmly and rigidly secured to the presser-foot bar.

The clamping bracket 2! has a bifurcated end portion 3| which extendsdownwardly and engages the shank l of the presser foot I4 on each sideof the head of the machine screw l3a. The end portion 3| backs up thepresser foot against the side thrust of the cutting action of the maleknife entering the female knife. It is to be noted (Fig. 1) that thepoint of convergence of the cutting edges 0 and of the female knife isin line with the axis of the presser-foot bar 4.

The bracket 24 extends at right angles to the plane containing the axisof the presser-foot and needle bars 4 and 5, respectively. The bracketis bifurcated, forming spaced, bearing arms 32 and 33. A bell-cranklever 34 is pivoted between the arms 32 and 33 on a pivot screw 35 thatextends through the arm 32 and that is threaded into the arm 33. One arm35a. of the lever 34 extends downwardly and is pivotally secured to anend extension 36 of the male knife 23. The other arm 3! of the lever 34has a gear sector 38 formed thereon. An integral guide extension 39extends from the cutting end of the male knife and into the femaleknife. This guide extension, which engages the edges of the femaleknife, in the retracted or withdrawn position of the male knife, servesto maintain the male knife in proper relation with respect to the femaleknife.

The male knife is resiliently urged, by a plunger 45, in a direction atright angles to its line of movement or to press the point ofconvergence of its cutting edges toward the point of the convergence ofthe cutting edges of the female knife. The relation of the angle of thecutting edges of the female knife to the angle of the cutting edges ofthe male knife is such that when the male knife enters the female knifethere is a shearing action, similar to that of shears, actingprogressively towards the point of convergence. The plunger 40 extendsvertically and is slidably mounted in a bushing 4| mounted in an opening42 through the bracket 24. A head 43 on the plunger 40 engages theupper, flat surface of the male knife, and a spring 44 surrounding theplunger acts between the bracket and the head of the plunger. Thus, whenthe male knife is reciprocated, and the edge of the material being sewnis fed past the female knife and parallel to the surface thereof, aseries of V-shaped notches are cut in the edge of the material.

The male knife is actuated through mechanism connected to the needlebar, preferably on alternate, penetrating strokes of the needle. Forthis purpose a split, pivot bracket 45, having a pivot 45 extending fromthe side thereof, is clamped on the needle bar by a clamping screw 41.One end of a lever 43 is pivotally secured on, the pivot 46 by a headscrew 49. The other end of the lever 48 is pivotally secured to the endof a rocker arm 50 that is rotatably mounted on the end of a shaft 5|journaled in the arms 32 and 33 of the bracket 24 and extending throughand beyond the arm 33. Intermediate the ends of the lever 48, there ispivotally secured thereto one end of a link 52. The other end of thelink 52 is pivotally secured to a lever 53 that is rotatably mounted onthe shaft 5|. The lever 53 has pivoted thereon a pawl 54 that cooperateswith a ratchet wheel or crank 55 fixed on the shaft 5| on one side ofthe lever 53, between the lever and the rocker arm 53, and a ratchetwheel 56 rotatably mounted on the shaft 5| on the opposite side of thelever 53, and between the lever 53 and the arm 33 of the bracket 24.

The pawl 54 extends across the ratchets 55 and '53 and the lever 53 is.cut away at 5? to permit the pawl to engage both ratchets. A bifurcatedextension 5? formed integral with the pawl has lateral extensions 53that straddle the lever 53 and that are pivotally secured to the leverby a pivot 53. The pawl is resiliently urged into ratchet engagingposition by a spring 3!] acting between a pin 6| extending from the endof the pawl and another pin 62 extending from the lever 53. The pawlmay, however, for a purpose that will hereinafter appear, be held awayfrom the ratchets, in a position in which it cannot engage the ratchets.This is effected through a manually operated throw-out lever 63 that ispivotally mounted between the arms of the bifurcated extension 57 of thepawl on a pivot 65. The throwout lever 53 includes a finger piece 65,through which it is actuated and a cam surface 35, pcsitioned to engagethe edge of the lever In the position shown in Figs. 2, 5 and 6, thepawl is in ratchet-engaging position. If the finger piece 65 is moved tothe left, the cam surface 63 engages the lever 53, raises the pawl, andmaintains the pawl, out of ratchet engaging position.

Also fixed on the shaft 5| is a sector gear 3? that is positionedbetween the arms 32 and 33 of the bracket 25 and which meshes with thegear sector 38 formed on the arm 37 of the lever 33. Thus, when thelever 53 is actuated through the link 52 and the lever 43 and the pawlengages the ratchet '55, the shaft 5|, on the down stroke of the needle,is rotated counterclockwise as seen in Figs. 2, 4, 5 and 6. Through thegear sectors 5? and 38, the lever 35 is rotated clockwise and moves themale knife into cutting relation with the female knife. During the downstroke of the needle, the feed dogs are not acting on the material beingsewn. Thus, the material is stationary while the cut is being effected.On the return stroke, the crank ratchet 55 is re turned through anabutment screw 63 (Fig. 6) that is threaded into the lever 53 and whichis positioned to engage the edge of the crank ratchet which is in theform of a sector of a disk, at a point substantially diametricallyopposite the point at which the pawl engages the disk.

The idler ratchet 53 is provided and arranged so that the pawl engagesthe crank ratchet 55 only on every other, or alternate penetratingstrokes of the needle. To this end, the successive teeth of the idlerratchet are of different depth, alternate teeth being of the same depth.Thus, the teeth 59 are relatively shallow compared to the teeth E3. Thedepth of the teeth 53 is such that when the pawl engages a tooth 69, itis held positioned above the engaging edge of the crank ratchet 55.However, when the pawl engages or drops over a tooth ill. it ispositioned to engage the crank ratchet 55. A stop or detent H pivotallymounted on a pivot l2 extending from the side of the arm 33 of thebracket 24 is positioned to engage the teeth 69 and iii of the idlerratchet 56 to prevent clockwise rotation thereof. The stop has anextension 13 thereon which extends under the lower edge of the arm 33. Aspring 14, engaging the extension and the bottom of a hole in the lever,resiliently urges the stop into ratchet engaging position. It will beapparent that by increasing the number of teeth 69 between the teeth 10,the ratio of oscillations of the male knife with respect to thereciprocations of the needle may be varied.

The arrangement, above described, is suitable for effecting a plainstitch and pinking operation; a top stitch and pinking operation; andstitching without pinking. The passage of the cloth through the presserfoot in the plain stitching operation is illustrated in Fig. 10. Twopieces of cloth 1'5 and 16 are laid one on top of the other with the endportions entered in the slot 22. As the cloth is moved through themachine by the feed dogs 3 the end edge portions of the two pieces ofcloth are turned, by the wall 22, vertically and guided between the maleand female knives of the pinker. In top stitching, one

piece of cloth I? is bent (Fig. ll) around the lower edge of the wall'22 and the under side of the foot. The other piece of cloth "is extendsdirectly under the foot and into the slot 2i on top of the fold T9 inthe piece i1. Again, the end portions of the two pieces of cloth areturned into a vertical position and guided to the pinker by the wall 22of the slot 2i. It is to be noted that the feed dog 3 spans the slot 2iand thus acts upon both pieces of cloth in this latter arrangement.

In Fig. 12, there is illustrated a simplified arrangement for effectingthe operation of plain stitching and pinking. With this arrangement asimple, unslotted p-resser foot 89 is used. A guide 81 is secured to thepresser foot. The end edges of the two pieces of cloth being sewn, whichend edges extend beyond the right of the presser foot, are turnedvertically and entered between the guide 8! and the female knife 8. Theguide 8| thus maintains the end edge portions vertical and guides thembetween the male and female knives.

When it is desired, to do plain sewing, i. e. without pinking, it isonly necessary to actuate the throw-out lever 63 above described. This,as explained, raises the pawl 5- and holds it in raised position, sothat it cannot engage the crank ratchet 55-. Thus, the actuatingmechanism for reciprocating the male knife is rendered inoperative.

From the foregoing description of the sewing and pinking machineillustrated in the drawing, it will be seen, by those skilled in theart, that by this invention a simple effective arrangement is providedby means of which various forms of stitching, as done on the ordinarysewing machine, may be eifected and the edge of the materialsimultaneously pinked. It will also be apparent that by this inventionthere is provided a simple arrangement by which the ordinary sewingmachine may be converted into a combined sewing and pinking machine.

It will be obvious that various'changes may be made by those skilled inthe art in the details of the embodiment of the invention illustratedinthe accompanying drawing and described above within the principle andscope of the invention as expressed in the appended claims.

I claim:

1. In a sewing machine having a slidably mounted needle-bar, feedingmeans for moving material to be sewn past the needle-bar, and means foreffecting reciprocation of the needlebar and operation of the feedingmeans in timed relation with respect to the reciprocation 0f theneedle-bar; the combination of edge-cutting mechanism comprising abracket, cooperating relatively movable cutting knives, and operatingmeans actuated from said needle-bar for effecting relative movement ofthe cutting knives in timed relation with respect to the reciprocationof said needle-bar and said feeding means and including mechanism forrendering the operating means ineffective upon certain reciprocations ofthe needle.

2. In a sewing machine having a needle-head, a needle-bar slidablymounted in the needle-head, a presser-foot bar adjacent the needle-bar,feeding means for moving material to be sewn past the needle-bar, andmeans for effecting reciprocation of the needle-bar and operation of thefeeding means; the combination comprising a bracket secured to thepresser-foot bar, a inovable cutting knife carried by the bracket, anoperating element connected to the needle-bar and actuating meanscarried by the bracket and connecting said operating element and saidmovable cutting knife, and including mechanism operative to effectcutting movement of said movable knife only on alternate strokes of theneedle.

3. In a sewing machine having a needle-head, a needle-bar slidablymounted in the needlehead, a presser-foot bar adjacent the needle-bar,feeding means for moving material to be sewn past the needle-bar, andmeans for effecting reciprocation of the needle-bar and operation of thefeeding means; the combination comprising a bracket fixed with respectto the needle-head, a reciprocable cutting knife carried by the bracket,a lever connected to the needle-bar, and actuating means carried by thebracket and connecting said lever and said reciprocable cutting knifeand including a pawl actuated by said lever, and a ratchet connected tosaid movable cutting knife and positioned to be engaged by said pawl.

4. In a sewing machine having a needle-head, a needle-bar slidablymounted in the needle-head, a presser-foot bar adjacent the needle-bar,feeding means for moving material to be sewn past the needle-bar, andmeans for effecting reciprocation of the needle-bar and operation of thefeeding means; the combination comprising a bracket fixed with respectto the needle-head, a movable cutting knife carried by the bracket, alever connected to the needle-bar, and actuating means'carried by thebracket and connecting said lever and said movable cutting knife andincluding a ratchet connected to said movable cutting knife, a pawlpositioned to cooperate with said ratchet and connected to said lever,and manually operative means including a shiftable element having afinger piece thereon for removing the pawl from cooperative relationwith said ratchet.'

5. In a sewing machine having a needle-head, a needle-bar slidablymounted in the needlehead, a presser-foot bar adjacent the needle-bar,feeding means for moving material to be sewn past the needle-bar, andmeans for effecting reciprocation of the needle-bar and operation ofthefeeding means; the Combination comprising a bracket fixed with respectto the needle-head, a movable cutting knife carried by the bracket, alever connected to the needle-bar, and 'actuating means carried by thebracket and connecting said lever and said movable cutting knife andincluding a ratchet connected to said movable cutting knife, a pawlpositioned to cooperate with said ratchet and connected to said lever,and means for withholding the pawl from cooperation with said ratchetonly on alternate strokes of the needle 6. In a sewing machine having aneedle-head, a needle-bar slidably mounted in the needle-head, apresser-foot bar adjacent the needle-bar, feeding means for movingmaterial to be sewn past the needle-bar, and means for effectingreciprocation of the needle-bar and operation of the feeding means; thecombination comprising a bracket fixed with respect to the needle-head,a movable cutting knife carried by the bracket, a lever connected to theneedle-bar, and actuating means carried by the bracket and connectingsaid lever and said movable cutting knife and including a ratchetconnected to said movable cutting knife, a pawl positioned to cooperatewith said ratchet and connected to said lever, and means for withholdingthe pawl from cooperation with said ratchet on alternate strokes of theneedle, including an idler ratchet having alternate teeth of differentdepth.

7. In a sewing machine having a needle head, a needle-bar slidablymounted in the needle-head, a presser-foot bar adjacent the needle bar,feeding means for moving the material to be sewn past the needle-bar,and means for effecting reciprocation of the needle-bar and operation ofthe feeding means; the combination comprising a presser-foot secured tothe presser-foot bar, a female "cutting knife carried by thepresser-foot bar and arranged in a plane parallel to the planecontaining the axis of the needle and presserfoot bars, a bracketsecured to the presser-foot bar, a movable cutting knife carried by thebracket and positioned to move into and out of said female knife, anelement connected to the needle bar, and actuating mechanism connectingsaid element and said movable knife.

8. In a sewing machine having a needle-head, a needle-bar slidablymounted in the needlehead, a presser-foot bar adjacent the needle bar,feeding means for moving the material to be sewn past the needle-bar,and means for effecting reciprocation of the needle-bar and operation ofthe feeding means; the combination comprising a presser-foot secured tothe presserfoot bar, a female cutting knife carried by the presser-footbar and arranged in a plane parallel to the plane containing the axis ofthe needle and presser-foot bars, a bracket secured to the presser-footbar, a movable cutting knife carried by the bracket and positioned tocooperate with said female knife, an element connected to the needlebar, and actuating mechanism connecting said element and said movableknife including a ratchet connected to said movable knife, a pawlpositioned to cooperate with said ratchet, and'an idler ratchet havingteeth of different depth for withholding the paul from cooperation withsaid ratchet on certain strokes of the needle.

9. An edge trimming attachment for a sewing machine of the kinddescribed which attachment includes a bracket adapted to be secured tothe presser-foot bar of a sewing machine, a movable knife carried by thebracket, a lever carried by the bracket and adapted to be secured to the8 needle-bar of the sewing machine, and actuating mechanism carried bythe bracket and connecting said lever and said knife and including meansfor eifecting cutting movement of the knife only on alternateoscillations of said lever.

10. An edge trimming attachment for a sewing machine of the kinddescribed which attachment includes a bracket adapted to be secured tothe presser-foot bar of a sewing machine, a movable reciprocable knifecarried by the bracket, a lever carried by the bracket and adapted to besecured to the needle-bar of the sewing machine and actuating mechanismcarried by the bracket and connecting said lever and said knife andincluding a ratchet connected to th knife and a pawl connected to thelever.

11. An edge trimming attachment for a sewing machine of the kinddescribed which attachment includes a bracket adapted to be secured tothe presser-foot bar of a sewing machine, a movable knife carried by thebracket, a lever carried by the bracket and adapted to be secured to theneedle-bar of the sewing machine and actuating mechanism connecting saidlever and said knife including a ratchet connected to said knife, a pawlpositioned to cooperate with said ratchet, and means for withholding thepaul from cooperation with said ratchet on certain strokes of the needleincluding an idler ratchet having alternate teeth of different depth.

12. An edge trimming attachment for a sewing machine of the kinddescribed which attachment includes a bracket adapted to be secured tothe presser-foot bar of a sewing machine, a movable knife carried by thebracket, a lever carried by the bracket and adapted to be secured to theneedle-bar of the sewing machine and actuating mechanism connecting saidlever and said knife including a ratchet connected to said knife, a pawlpositioned to cooperate with said ratchet, means for withholding thepaul from cooperation with said ratchet on certain strokes of the needleincluding an idler ratchet having alternate teeth of different depth,and manually operative means including a shiftable element having afinger piece thereon for rendering said pawl ineffective.

13. An edge-trimming attachment for a sewing machine of the kinddescribed, which attachment includes a bracket adapted to be attached tothe presser-foot bar and th following mechanism carried by the bracket,a stationary knife, a reciprocable knife positioned to cooperate withthe stationary knife, a lever adapted to be connected to the needle-barof a sewing machine, and actuating mechanism connecting said lever andsaid reciprocable knife including means for actuating the knife only oncertain movements of the lever.

THOMAS D. TAYLOR.

REFERENCES CITED The following references are of record in the file ofthis patent:

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